Drug delivery devices allowing for multiple dosing of a required dosage of a liquid medicinal product, such as liquid drugs, and further providing administration of the liquid to a patient, are as such well-known in the art. Generally, such devices have substantially the same purpose as that of an ordinary syringe.
Pen-type injectors of this kind have to meet a number of user specific requirements. For instance in case of those with diabetes, many users will be physically infirm and may also have impaired vision. Therefore, these devices need to be robust in construction, yet easy to use, both in terms of the manipulation of the parts and understanding by a user of its operation. Further, the dose setting must be easy and unambiguous and where the device is to be disposable rather than reusable, the device should be inexpensive to manufacture and easy to dispose. In order to meet these requirements, the number of parts and steps required to assemble the device and an overall number of material types the device is made from have to be kept to a minimum.
In particular with disposable devices manufacturing and production costs have to be kept at a minimum. Hence, drug delivery devices, such as pen-type injectors are nowadays typically manufactured by way of a fully automatic production.
Due to inevitable tolerances in the outer dimensions of the components of such devices and due to tolerances in the assembly procedure itself, presence, position as well as orientation of particular components of such devices have to be visually controlled and inspected in order to allow for a precise assembly that fulfils given quality standards for such medical devices.
Visual inspection and manufacturing control is typically conducted by way of automatic image acquisition and digital processing of acquired images. This method however requires that the components to be visually inspected provide sufficient contrast with respect to a surrounding environment. This requirement limits the range of materials and colours adequate for respective device components.
Additionally, an increase of counterfeited drug delivery devices and drugs has been recently observed that are typically of substandard quality. Counterfeited drugs and devices carry a significant risk to health and may further damage reputation of the original equipment and drug manufacturer.
Another problem has been observed with drugs and medical devices featuring an exceeded expiration date. The medical device but also respective medical substances, such as drugs, should no longer be used once their expiration date has been reached. Patients using drugs and medical devices on a rather irregular but long-term time schedule, may therefore be exposed to a certain risk of health if not being explicitly and timely informed about an approaching expiration date.